The world uses ~2,000 GW and has ~100 GW of PSH capacity. Scaling up by a factor of 20 would be expensive because the low hanging fruit has been taken, but it really doesn't seem that bad if it means our base generators are half (or less) as expensive. See, for example, this take in Scientific American:
Do you have a reference you could link me to?
Also, any reason to think this can't be solved by pumped-storage hydroelectricity?
http://en.wikipedia.org/wiki/Pumped-storage_hydroelectricity
The world uses ~2,000 GW and has ~100 GW of PSH capacity. Scaling up by a factor of 20 would be expensive because the low hanging fruit has been taken, but it really doesn't seem that bad if it means our base generators are half (or less) as expensive. See, for example, this take in Scientific American:
http://www.scientificamerican.com/article.cfm?id=here-is-the...
Hell, even storing it in batteries isn't that expensive:
http://www.bloomberg.com/news/2013-01-23/duke-completes-bigg...
($44 million for 36 MW, which is added to the typical costs of wind turbines of ~$2 million per MW.)